1. Field of the Invention
This invention relates to a light-emitting device and a method for producing a light-emitting device.
2. Background Art
By improvement of characteristics of nitride light-emitting device, light equipment using a semiconductor light-emitting device has become possible. For further expanding lighting purpose, improvement of optical output and light-emitting efficiency of the light emitting device has been required. Moreover, in lighting purpose, high mass productivity is required.
As a substrate for performing crystal growth of a nitride light-emitting device, sapphire of insulator material or the like is often used. However, if an insulator substrate, it is difficult to set the vertical direction to the substrate to be a current pathway, and its current pathway becomes through high serial resistance along a surface parallel to the substrate. Therefore, the light-emitting efficiency lowers. On the other hand, if the nitride semiconductor substrate having conductivity is used, low resistance is possible but growth in size of the substrate is difficult and mass productivity is insufficient.
There is a technique disclosure example about a III-V group compound semiconductor device having high light-emitting efficiency and a method for producing the device (JP-A 2006-135026 (Kokai)). In this disclosure example, there is disclosed a method for producing a light-emitting device, including bonding a ground substrate in which a laminated body of III-V group compound semiconductor is formed and a semiconductor substrate in which a laminated body containing metal layer is formed and then removing the ground substrate.
However, even if the technique disclosure example is used, it is not sufficient for the light-emitting device and the producing method which have characteristics and mass productivity satisfying requirement of light purpose.